For questions about the function RegularExpression which is used in string patterns in functions as StringCases, StringReplace, StringPosition,StringCount etc.

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14
votes
2answers
363 views

Shell Emulation inside Mathematica

I am trying to create a Mathematica/shell syntax hybrid. I would like the following command wget -qO- "http://google.com/space line break\"" $var to be ...
4
votes
1answer
78 views

Extracting integers from a string

Imagine I have a block of text that contains words and numbers. I want to extract all the integers from the text. Thus, if the input is ...
12
votes
0answers
117 views

Can Mathematica convert a RegularExpression into a StringExpression or vice-versa?

I know that Mathematica can perform string comparison using either StringExpression or RegularExpression. Although regular ...
2
votes
2answers
44 views

Date Conversion Using Regular Expressions on “Incomplete” Date Formats

I have a list of dates in one of the following formats: "1999/05/12", "1999/05/", "1999//", "****//**/", "" so that a list of such dates might appear as ...
3
votes
2answers
94 views

How remove specified substring and everything after it to the end of a string?

If I have, say, the string, txt = "now is the time for all (good) men" then I want to remove the substring beginning with "for" and ending at the end of the ...
0
votes
1answer
37 views

Regular expression help for arecord command output

How do I get the card number and device number alone from this string by using a regular expression to parse it? Here's the string ...
4
votes
2answers
106 views

Using parenthesized Regex backreferences in StringReplace

(I am sorry for my poor English,I'll try to use a simple sentence to convey me.) I can use StringCases to get the target to change like this ...
2
votes
0answers
51 views

Error importing MBOX file

I am trying to import the mbox file generated by gmail. Using the Import command. ...
2
votes
1answer
59 views

Associations - getting values according to a key pattern

I want to get all counts of trigrams that with "th" (or any other given digram). ...
3
votes
2answers
263 views

Please help translate regular expression to StringExpression

I am familiar with regular expressions in other languages (e.g., Perl, Python, ViM), but the Mathematica StringExpression is baffling me. I'd like to match strings ...
1
vote
1answer
84 views

Are all of the numbers in my file legitimate hex numbers

I have about 10,000 hexadecimal numbers (32 digits each) in an excel file, in one column. I want to verify that all of them are indeed hexadecimal number and that no other characters are present. My ...
10
votes
2answers
207 views
7
votes
3answers
238 views

Does RegularExpression support “(?R)”?

Mathematica's RegularExpression is based on Perl's PCRE library, which supports recursive regular expressions using (?R) (or, ...
3
votes
2answers
266 views

how to extract the string using regular expressions

I have the list : a1 = {"struct name1 {","struct name2{","struct name3{","struct name4{", "struct name5{","struct lastStruct{"} I tried to extract the ...
2
votes
1answer
112 views

Regular Expression - for html objects

I did a previous research about similar questions, but I really am confuse about using html objects. I have the following situation: I Import a html from a url and I need to pick the numbers that ...
32
votes
1answer
688 views

Why is StringExpression faster than RegularExpression?

Edit: as noted by Albert Retey the performance difference is only seen when sub expression extraction is performed. If this test is used below the timings are similar: ...
0
votes
1answer
107 views

What does the expression “Total[funca[a,#] & /@ #] & /@ {x,y}” possibly mean?

Can the expression be simplified as "Total[funca[a,#]] & /@ {x,y}"? What does the double of "& /@" mean? Where can I find some reference? Updated According to Mr.Wizard's answer, I now know ...
1
vote
2answers
118 views

text analysis: split document in seperated lines

For a text analysis I want to split a large document in seperated lines. Then I want to calculated for example the average number of words. A example of the document is the following: ...
2
votes
2answers
59 views

Retain or delete parts of textstring in tweets

For a twitter analysis I collected many tweets. For example: ...
5
votes
2answers
435 views

Find file names in directory

I am trying to find the list of any file in any directory of a given name (by in the directory, I mean directly in the directory, so in a directory which is in the directory would not count). For the ...
3
votes
1answer
77 views

Convert an expression's symbols of form a$x to a[x]

I want a function that takes expressions of the following form: a$x and converts them to a[x]. In particular, consider the ...
10
votes
1answer
378 views

Wikipedia People only search

I am trying to search people from Wikipedia(For example .*John.* in REGEX). The following query is close, but it isn't generalized like ...
2
votes
1answer
77 views

StringExpression: pattern reapeted one or more times matches pattern repeated zero times

I try to construct patterns using Riffle and Except StringExpression@Riffle[{"a", "b", "c"}, Except[{"=", ","}] ..] and expect it to match "a_b_c", but not ...
3
votes
3answers
192 views

StringCases using RegularExpression fails when there is missing data

I got some text scraps with this structure "Focal Plane: 198' Active Aid to Navigation: Yes *Latitude: 35.250 N *Longitude: -75.529 W" But some of them lack ...
3
votes
2answers
134 views

Mathematica regex equvalent of \l

In normal RegEx \l will make the character to the right lowercase. However, it seems like the RegEx in Mathematica does not have this functionality. For example ...
3
votes
1answer
352 views

Extract date from a not well-formed string

Is there a way to robustly extract date and time from a text? Say for example: ...The event will be held on 17/10/2013 at 3:30 PM in the room 121 and everyone is welcome... should return: ...
2
votes
1answer
92 views

Make MyLogicalExpand

The function by Mathematica to expand a formulation with ANDS, ORS, NOT, XOR, and others, is LogicalExpand, let see an example: ...
4
votes
5answers
367 views

A simple StringCases problem

Given this text: text1 = " A Vitamin D Deficiency (ICD-9-CM 268.9) (ICD-9-CM 268.9) 09/11/2015 01 "; Yes, the ICD code values are duplicates- possibly but ...
11
votes
1answer
1k views

Mathematica equivalent of regex '\w{2,3}'

It beats me to write the Mathematica pattern equivalent to the regex: \w{2,3} Any ideas?
8
votes
1answer
4k views

What pattern will match accented letters in a regular expression?

How should I modify the following such that the accented letter É is matched and the expression returns True? ...
5
votes
4answers
1k views

Creating lists from a string, separating words from numbers

Say I have a string that contains numbers and words, such as this one: string = "there are 1234 words and numbers 5678 in here $999"; How would I separate the ...
13
votes
2answers
503 views
5
votes
2answers
451 views

Tabs inside expression to format code

In a similar spirit to a question proffered several days back,and as that question stated, Since the front-end is quite extendable my question is... Does the front end provide any way to use ...
17
votes
4answers
1k views

Finding all dictionary words that can be made with a given set of characters (Wordfeud/Scrabble)

This is a slightly more involved variant of this recent question. By sheer coincidence I happened to have been building a Wordfeud (Scrabble clone) game in Mathematica. My interactive Wordfeud ...